Quantum Measurement of Broadband Nonclassical Light Fields

TL;DR

This paper investigates quantum correlation measurements of broadband nonclassical light, comparing spectral filtering methods and analyzing conditions for detecting nonclassicality, with a focus on atomic resonance fluorescence.

Contribution

It provides a comparative analysis of spectral filtering versus direct detection for broadband quantum light, highlighting the advantages of photocurrent filtering in detecting nonclassical features.

Findings

Photocurrent filtering is more effective than optical spectral filtering for detecting nonclassicality.

Vacuum-noise effects limit the effectiveness of optical filtering.

Conditions for observing nonclassical signatures are identified.

Abstract

Based on the measurement of quantum correlation functions, the quantum statistical properties of spectral measurements are studied for broadband radiation fields. The spectral filtering of light before its detection is compared with the direct detection followed by the spectral analysis of the recorded photocurrents. As an example, the squeezing spectra of the atomic resonance fluorescence are studied for both types of filtering procedures. The conditions for which the detection of the nonclassical signatures of the radiation is possible are analyzed. For the considered example, photocurrent filtering appears to be the superior option to detect nonclassicality, due to the vacuum-noise effects in the optical filtering.